>>12715236a physicist computing probabilities for whether the radioactive decay has occurred or not needs to take into account that the decay process is a random poisson process, so unless he opens the box to check, quantum theory models the radioactive thing in a superposition state of partially decayed and also simultaneously partially not decayed.
the confusion here is whether the contents of the box are actually in a superposition, or whether decoherence happens before the physicist modeling the situation opens the box.
clearly in the schrodinger car case, the superposition state is decohered upon interaction with the radioactive particle by whatever device is monitoring it. superposition states are very fragile and decohere rapidly without very specific experimental setups to isolate the superpositioned system from interactions
reminder that schrodinger came up with this to point out an obvious problem with the interpretation theory, but decades later this was all made sense of in the context of decoherence
